1. Field of the Invention
The present invention relates to a video game apparatus which displays information indicating a boundary between a plurality of fields formed in a virtual three-dimensional space on a screen according to movement of a player character.
2. Description of the Related Art
In a role playing game, generally, a game progresses as a player solves various problems set at predetermined positions in a virtual space while moving a player character in the virtual space. A plurality of areas (fields) are set in the virtual space of the game, and the player character can move over a boundary (or border) between areas to move therebetween.
The image of an area where the player character is positioned is generated based on graphic data stored in a main memory constituted by a volatile storage medium which generally has a fast data reading speed. The memory capacity of a volatile storage medium having a fast data reading speed is generally small, so that graphic data of individual areas formed in a virtual space are stored in separate areas in a non-volatile storage medium, such as large-capacity CD-ROM or DVD-ROM, which generally has a low data reading speed.
The graphic data of an area where the player character is positioned (and an area adjacent to the area) is loaded into the main memory from the non-volatile storage medium as needed. Because of the relatively slow data reading from those non-volatile storage mediums, loading graphic data of a new area into the main memory takes a considerable time during which the progress of the game the player has been playing would inevitably be interrupted.
If the player moves the player character from the current area to another area without noticing the presence of the boundary between the areas, the player should wait until graphic data of the area to which the player character has moved is loaded into the main memory. If the player tries to return the player character to the previous area, graphic data thereof needs to be loaded again. If the player performs some operation to move the player character from one area to another area without noticing the presence of the boundary between the areas, despite the fact that moving the player character between the areas is not particularly necessary, quick progress of the game is interfered considerably.
Japanese Patent Laid-Open Publication No. 2005-319018 discloses a video game which displays a screen at whose upper and lower portions a non-display area (NDA) having a width according to the distance between a player character and an area boundary (exit EXT) are generated when the player character comes within a predetermined range near the area boundary. The video game disclosed in Japanese Patent Laid-Open Publication No. 2005-319018 allows the player to identity the approach of the player character to the area boundary more easily.
However, a person in a real world sees a continuous landscape even if a border is set in a wilderness, and the field of view of the person is not narrowed even when the person approaches the border. In consideration of such a circumstance in a real world, the non-display area (NDA) disclosed in Japanese Patent Laid-Open Publication No. 2005-319018 gives awkward feeling to the player.